You can get the registration number of TS EAMCET from two sources:

1. After registering in TS EAMCET you would have received an Email from the TS EAMCET in your registered mobile/registered email address.
2. when you have paid the examination fee for TS EAMCET you may have get a confirmation page which contains all such details.
3. You can go to the website and click on forgot application number. Follow the procedure and you will get your application number.

To know more about TS EAMCET 2021 visit the link provided below:

https://engineering.careers360.com/articles/ts-eamcet

I hope this answer helps. All the very best for your future endeavors!